A few months ago I setup a new computer for my 73 year Mother and instead of installing Windows I decided to put Linux on the box. I wrestled with doing this for a while as I didn't want to have my Mom getting confused with a new interface. Previously windows had been installed on the old box. Another factor was that I am in Johannesburg while my Mom and Dad are in Durban.
Mark Clarke's blog
Today we experienced some mail delivery problems on one of our client's servers running Centos 4 and postfix with amavisd for virus and spam scanning.
Trawl the log files
The mail logs where filling with errors such as:
(delivery temporarily suspended: lost connection with 127.0.0.1[127.0.0.1] while sending RCPT TO)
Java Persistence API detached object gotchas
One of the issues to get your head around in both Hibernate and JPA is how to handle detached entities. In Hibernate one has to deal with the session object and in JPA it is called the persistence context.
A common error when using EJB3 is
Cannot find the declaration of element 'persistence'
This is caused by a missing xml namespace attribute declaration in your persistence.xml file. To fix this error make sure your persistence tag has the following syntax:
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">
While surfing the net I came across this interesting lay study on the number of IP addresses per capita. From the map it appears that South Africa does quiet well for this unit of measure. According to the map we have 1 IP address for between 1-10 people. This puts us in the same bracket as Europe and behind the US and OZ.
Spam is the ban of any system administrators life and many people have taken it for granted that they must simply live with a certain level of spam in their day-to-day lives. However this does not have to be the case. A combined spam filtering approach is what is needed to end the spam problem. We find that a combination of blacklists and greylisting is the magic bullet that kills spam dead.
Recently we had upgraade a db2 8.1 database running on Windows to db2 9 running on a Linux based server. From the IBM documentation it appeared that it was possible to upgrade the database and change platforms but it was quiet difficult to find out exactly how.